An autonomically-healed PMMA bone cement: influence of the crystal size of Grubbs' catalyst on fracture toughness and polymerisation rate

2009 ◽  
Vol 2 (6) ◽  
pp. 494 ◽  
Author(s):  
Patrick Biggs ◽  
LeRoy Jones II ◽  
Gladius Lewis
Author(s):  
Sunjung Kim ◽  
Caroline Baril ◽  
Shiva Rudraraju ◽  
Heidi-Lynn Ploeg

Abstract Aseptic loosening is the most common reason for long-term revision of total joint replacement (TJR). Infection is the main reason for short-term revision of TJR. In our previous studies, experimental results showed that acrylic bone cement-loaded with antibiotics had a detrimental effect on cement strength such as bending strength, compressive strength, and fracture toughness. This result implied that the mechanical failure of antibiotic loaded bone cement was potentially related to porosity volume fraction. Hence, the objective of this study was to investigate the effect of pore size and distribution on bone cement fracture toughness. The effect of pores was analyzed using the extended Finite Element Method (X-FEM) method to model crack propagation and its modulation by pore sizes and locations. Numerically obtained load-displacement responses were compared to experimental results. We observed that crack propagation is affected by several pore parameters; as expected these include pore size and pore locations (pore-pore interactions) and are related to implicit pore-crack interactions. The experimental and numerical investigations presented in the current study contribute to a better understanding of the effect of pores on bone cement fracture toughness; key insights include the identification of a critical pore size for reduced fracture toughness, and relative insensitivity of crack propagation to stochastically distributed pore locations.


Author(s):  
Morshed Khandaker ◽  
Yanling Li ◽  
Ping Liu ◽  
Melville B. Vaughan

The most common bone cement material used clinically today for orthopedic surgeries is poly methyl methacrylate (PMMA). In general, poly Methyl MethAcrylate (PMMA) beads are added to MMA monomer with bead and monomer ratio of 2:1 to prepare the PMMA bone cement. Conventional PMMA bone cement has several mechanical and biological disadvantages. To overcome these disadvantages, researchers investigated several bioactive additives to PMMA bone cement, such as MgO, hydroxyapatite (HAp), chitosan (CS). Additionally, functional monomer, such as glycidyl methacrylate (GMA) was used in addition or substitution to MMA to enhance the properties of PMMA bone cement. A comparative study is required to evaluate the effect that different bioadditives and monomers have on the mechanical and biological performances on PMMA bone cement. The goal of this study is to determine the most suitable additives and alternative monomer for PMMA bone cement that can enhance the mechanical and biological performances of PMMA bone cement. Cobalt™ HV bone cement (referred as CBC), a commercial orthopedic bone cement, was used in this study as PMMA bone cement. MgO, hydroxyapatite (HAp), chitin (CT), chitosan (CS), Barium sulfate (BaSO4) and Silica (SiO2) were mixed with PMMA beads to prepare CBC-MgO, CBC-HAp, CBC-CT, CBC-CS, CBC-BaSO4 and CBC-SiO2 specimens. Additives included CBC were referred as composite specimen. CBC and composite specimens were further grouped according to the application of GMA as replacement of MMA monomer. Two groups of CBC and composite specimen were prepared. In the first group, CBC and composite specimens were prepared using MMA monomer only, referred as without GMA specimen. In the second group, CBC and composite specimens were prepared using GMA and MMA monomers, referred as with GMA specimen. There are three general research questions: (1) Is there a significant difference in the mechanical and biological performances between CBC (control) and different composite specimens that contain GMA? (2) Is there a significant difference in the in the mechanical and biological performances between CBC (control) and different composite specimens that do not contain GMA? and (3) Is there a significant difference in the mechanical and biological performances between specimens mixed with and without GMA? Elastic and fracture properties of different CBC and composite cements were calculated from three point bend experiments. Osteoblast cell adhesion experiments were performed on different CBC and composite cement on a custom made well plate. This study found that flexural strength and fracture toughness of the CBC specimens that contain GMA is significantly greater than the flexural strengths of all other specimens that contain GMA. In contrast, flexural strength and fracture toughness of the CBC-SiO2 specimens that do not contain GMA is significantly greater than the flexural strengths of all other specimens that contain GMA. This study also found that cell adhesion on the MgO impregnated CBC specimens is significantly greater than the cell adhesion of all other specimens for samples that contain GMA or do not contain GMA.


Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2027
Author(s):  
Jaime Orellana ◽  
Ynés Yohana Pastor ◽  
Fernando Calle ◽  
José Ygnacio Pastor

Bone cement, frequently based on poly (methyl methacrylate), is commonly used in different arthroplasty surgical procedures and its use is essential for prosthesis fixation. However, its manufacturing process reaches high temperatures (up to 120 °C), producing necrosis in the patients' surrounding tissues. To help avoid this problem, the addition of graphene could delay the polymerisation of the methyl methacrylate as it could, simultaneously, favour the optimisation of the composite material's properties. In this work, we address the effect of different percentages of highly reduced graphene oxide with different wt.% (0.10, 0.50, and 1.00) and surface densities (150, 300, 500, and 750 m2/g) on the physical, mechanical, and thermal properties of commercial poly (methyl methacrylate)-based bone cement and its processing. It was noted that a lower sintering temperature was achieved with this addition, making it less harmful to use in surgery and reducing its adverse effects. In contrast, the variation of the density of the materials did not introduce significant changes, which indicates that the addition of highly reduced graphene oxide would not significantly increase bone porosity. Lastly, the mechanical properties (strength, elastic modulus, and fracture toughness) were reduced by almost 20%. Nevertheless, their typical values are high enough that these new materials could still fulfil their structural function. In conclusion, this paper presents a way to control the sintering temperature, without significant degradation of the mechanical performance, by adding highly reduced graphene oxide so that local necrosis of bone cement based on poly (methyl methacrylate) used in surgery is avoided.


2021 ◽  
Vol 1094 (1) ◽  
pp. 012150
Author(s):  
S K Al-Janabi ◽  
M H Al-Maamori ◽  
A J Braihi
Keyword(s):  

2006 ◽  
Vol 309-311 ◽  
pp. 801-804 ◽  
Author(s):  
S.B. Cho ◽  
Akari Takeuchi ◽  
Ill Yong Kim ◽  
Sang Bae Kim ◽  
Chikara Ohtsuki ◽  
...  

In order to overcome the disadvantage of commercialized PMMA bone cement, we have developed novel PMMA-based bone cement(7P3S) reinforced by 30 wt.% of bioactive CaO-SiO2 gel powders to induce the bioactivity as well as to increase mechanical property for the PMMA bone cement. The novel 7P3S bone cement hardened after mixing for about 7 minutes. For in vitro evaluation, apatite forming ability of it was investigated using SBF. When the novel 7P3S bone cement was soaked into SBF, it formed apatite on its surfaces within 1 week Furthermore; there is no decrease in its compressive strength within 9 weeks soaking in SBF. It is though that hardly decrease in compressive strength of 7P3S bone cement in SBF is due to the relative small amount of gel powder or its spherical shape and monosize. In vivo evaluation of the novel 7P3S bone cement was carried out using rabbit. After implantion into rabbit tibia for several periods, the interface between novel bone cement and natural bone was evaluated by CT images. According to the results, the novel bone cement directly contact to the natural bone without fibrous tissue after implantation for 4 weeks. This results indicates that the newly developed 7P3S bone cement can bond to the living bone and also be effectively used as bioactive bone cement without decrease in mechanical property.


2018 ◽  
Vol 68 (15) ◽  
pp. 924-930 ◽  
Author(s):  
J. A. Solís-Ruiz ◽  
G. M. Alonzo-Medina ◽  
A. May-Pat ◽  
L. Dominguez-Cherit ◽  
N. Acuña-Gonzalez ◽  
...  

Author(s):  
C Minari ◽  
M Baleanil ◽  
L Cristofolini ◽  
F Baruffaldi

New bone cements that include several additives are currently being investigated and tested. One such additive is sodium fluoride (NaF), which promotes bone formation, facilitating implant integration and success. The influence of NaF on the fatigue performance of the cement as used in biomedical applications was tested in this paper. In fact fatigue failure of the cement mantle is a major factor limiting the longevity of a cemented implant. An experimental bone cement with added NaF (12wt%) was investigated. The fatigue strength of the novel bone cement was evaluated in comparison with the cement without additives; fatigue tests were conducted according to current standards. The load levels were arranged based on a validated, statistically based optimization algorithm. The curve of stress against number of load cycles and the endurance limit were obtained and compared for both formulations. The results showed that the addition of NaF (12 wt %) to polymethylmethacrylate (PMMA) bone cement does not affect the fatigue resistance of the material. Sodium fluoride can safely be added to the bone cement without altering the fatigue performance of the PMMA bone cement.


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